Billbugs Control | Liqui Green Turf & Tree Care 2018-06-08T16:05:48+00:00

How to Control Billbugs

Quick Facts About Bill Bugs & White Grub

  • Billbugs damage grass by feeding on roots
  • Billbugs can attract wild mammals that will rip up lawns in order to eat the bugs on the roots.
  • It is best to treat lawn when billbug adults are present.
  • Young billbug larvae are known as “grub.”
  • Grub are almost impossible to control because they’re protected within the plants.

Need Lawn Treatment Against Billbugs?


What are Billbugs?

Billbugs are a type of beetle. They are commonly seen during spring or late summer. Adult billbugs cause damage to lawns by eating the roots and cutting holes in the stems of plants to lay eggs.  A young

A young billbug “grub” is a white or cream colored larvae that cause the most damage to lawns and plants. One of the most damaging places for a plant to be harmed is at the crown, which is the primary feeding area of young billbugs, eventually killing the plant. When fully grown, a billbug will reach 1/3 to 1/2 inch in length and begin feeding on the lower part of the crown.

To tell if a plant is infested with billbugs, study the stems of the plants, they are detached from the soil surface and the ends appeared sawed-off. Damaged, dying plants that are infested with billbugs may also have small piles of what looks like sawdust.

Bluegrass Billbug Control

Image by: Joseph Berger,

Common Types of Billbug in Colorado

Bluegrass Billbug (Sphenophorous parvulus)

Bluegrass billbug are one of two common species found in Colorado lawns. Bluegrass Billbug are resilient during cold winter seasons. They will overwinter under debris, grass turf, or sidewalks. When the weather warms up, eggs are produced from May-July. During late June and July, the larvae become active, digging deep into the soil and destroying plants. After about two or three weeks, adult billbugs will emerge from the soil and feed until the season begins cooling down, to which they will seek shelter for the winter.

Image by: Whitney Cranshaw, Colorado State University,

Rocky Mountain Billbug (Sphenophorous cicastriatus)

Rocky Mountain Billbug (otherwise known as “Denver Billbug”) is more common in Colorado than the bluegrass billbug. The Denver billbug has a less predictable life cycle than other billbugs. Where most billbug species will grow into adulthood during the warm season and seek shelter for the winter, Denver Billbug remains in the larval stage and feed throughout all of Spring. Adult Denver Billbug will lay their eggs during the entire growing season, preparing the next generation.

Image by: Whitney Cranshaw, Colorado State University,

Timing Insecticide Applications for Billbugs

Billbug Species Target Stage Best Time for Treatment
Denver Billbug Adults June-August
Bluegrass Billbug Adults May-June
Annual White Grub Young Larvae July-August
May-June Beetles Larvae at surface July-August